Triagem molecular de portadores assintomáticos de Plasmodium sp. entre Bancos de Sangue da região Amazônica brasileira

The transmission of malaria in Brazil is heterogeneous throughout endemic areas and the presence of asymptomatic Plasmodium sp. carriers (APCs) in the Brazilian Amazon has already been demonstrated. Malaria screening in blood banks is based on the selection of donors in respect to possible risks associated with travel or residence, clinical evidence and/or inaccurate diagnostic methods thereby increasing the probability of transfusion-transmitted infection. We evaluated the frequency of APCs in four blood services in distinct areas of the Brazilian Amazon region. DNA was obtained from 400 human blood samples for testing using the phenol-chloroform method followed by a nested-PCR protocol with species-specific primers. The positivity rate varied from 1 to 3% of blood donors from the four areas with an average of 2.3%. All positive individuals had mixed infections for Plasmodium vivax and Plasmodium falciparum. No significant differences in the results were detected among these areas; the majority of cases originated from the transfusion centres of Porto Velho, Rondônia State and Macapá, Amapá State. Although it is still unclear whether APC individuals may act as reservoirs of the parasite, efficient screening of APCs and malaria patients in Brazilian blood services from endemic areas needs to be improved.A transmissão da malária no Brasil é heterogênea em todas as áreas endêmicas e a presença de portadores assintomáticos de Plasmodium sp. (PAPs) na Amazônia brasileira já foi demonstrada. A triagem de pacientes maláricos em bancos de sangue é baseada na seleção dos doadores com relação aos riscos possíveis associados com residência, evidência clínica e/ou os métodos diagnósticos não acurados que aumentam a probabilidade da infecção transmitida por transfusão. Avaliamos a freqüência de PAPs em quatro bancos de sangue em áreas distintas da região Amazônica brasileira. O DNA foi obtido a partir de 400 amostras de sangue humano usando o método do fenol-clorofórmio, seguido por um protocolo de nested-PCR com oligonucleotídeos espécie-específicos. A taxa de positividade variou de 1 a 3% de doadores do sangue das quatro áreas, com uma média de 2,3%. Todos os indivíduos positivos tinham infecções mistas entre o Plasmodium vivax e o Plasmodium falciparum. Nenhuma diferença significativa nos resultados foi detectada entre estas áreas; a maioria dos casos originou dos Hemocentros de Porto Velho, do Estado de Rondônia e de Macapá, Estado do Amapá. Embora ainda não esteja claro se os indivíduos PAPs possam agir como reservatórios do parasito, a triagem eficiente de PAPs e de pacientes com malária em bancos de sangue no Brasil das áreas endêmicas necessita ser implementada

Diagnóstico laboratorial de hemoglobinopatias em populações diferenciadas

The inherited haemoglobinopathies are a heterogeneous group of recessive disorders that include the thalassaemias and sickle cell disease. Nearly a thousand mutant alleles have now been characterized. The mutations are regionally specific and in most cases the geographical and ethnic distribution shave been determined providing the foundation for a program of control through screening, genetic counseling and prenatal diagnosis. The diagnosis of hemoglobinopathies requires care for the methodologies applied and the population group which will be evaluated. The information about the abnormal hemoglobin, the medical and psychological aspects and genetic counseling of the carriers and their families are goals of great importance for the success of preventive programs in this area. Aiming to evaluate the laboratory methods for hemoglobinopathy screening and their use in clinical laboratories, we have compared abnormal hemoglobins incidence in the different population groups: blood donors, anemia carriers, newborn and students. The laboratory methods applied involved eletrophoretic proceedings, cytological and biochemical analysis. Within the period from September 1999 through January 2000, we analyzed 524 individuals with varied types of abnormal hemoglobins. Among blood donors, we diagnosed two sickle cell carriers, which suggest the necessity for better care in the process of selection of blood donor candidates. The current interest in the medical and social aspects of sickle cell anemia has resulted in a great increase in methodology research leading to the development of sickle cell screening techniques

Frequencies of ABO, MNSs, and Duffy Phenotypes Among Blood Donors and Malaria Patients from Four Brazilian Amazon Areas

We compared the serological phenotypic frequencies of ABO, MNSs, and Duffy in 417 blood donors and 309 malaria patients from four Brazilian Amazon areas. Our results suggest no correlation between ABO phenotype and malaria infection in all areas studied. We observed significant correlation between the S s , S s , and S s phenotypes and malaria infection in three areas. Some of the Duffy phenotypes showed significant correlation between donors and malaria patients in different areas. These data are an additional contribution to the establishment of differential host susceptibility to malaria

Molecular screening of Plasmodium sp. asymptomatic carriers among transfusion centers from Brazilian Amazon region

A transmissão da malária no Brasil é heterogênea em todas as áreas endêmicas e a presença de portadores assintomáticos de Plasmodium sp. (PAPs) na Amazônia brasileira já foi demonstrada. A triagem de pacientes maláricos em bancos de sangue é baseada na seleção dos doadores com relação aos riscos possíveis associados com residência, evidência clínica e/ou os métodos diagnósticos não acurados que aumentam a probabilidade da infecção transmitida por transfusão. Avaliamos a freqüência de PAPs em quatro bancos de sangue em áreas distintas da região Amazônica brasileira. O DNA foi obtido a partir de 400 amostras de sangue humano usando o método do fenol-clorofórmio, seguido por um protocolo de nested-PCR com oligonucleotídeos espécie-específicos. A taxa de positividade variou de 1 a 3% de doadores do sangue das quatro áreas, com uma média de 2,3%. Todos os indivíduos positivos tinham infecções mistas entre o Plasmodium vivax e o Plasmodium falciparum. Nenhuma diferença significativa nos resultados foi detectada entre estas áreas; a maioria dos casos originou dos Hemocentros de Porto Velho, do Estado de Rondônia e de Macapá, Estado do Amapá. Embora ainda não esteja claro se os indivíduos PAPs possam agir como reservatórios do parasito, a triagem eficiente de PAPs e de pacientes com malária em bancos de sangue no Brasil das áreas endêmicas necessita ser implementada.The transmission of malaria in Brazil is heterogeneous throughout endemic areas and the presence of asymptomatic Plasmodium sp. carriers (APCs) in the Brazilian Amazon has already been demonstrated. Malaria screening in blood banks is based on the selection of donors in respect to possible risks associated with travel or residence, clinical evidence and/or inaccurate diagnostic methods thereby increasing the probability of transfusion-transmitted infection. We evaluated the frequency of APCs in four blood services in distinct areas of the Brazilian Amazon region. DNA was obtained from 400 human blood samples for testing using the phenol-chloroform method followed by a nested-PCR protocol with species-specific primers. The positivity rate varied from 1 to 3% of blood donors from the four areas with an average of 2.3%. All positive individuals had mixed infections for Plasmodium vivax and Plasmodium falciparum. No significant differences in the results were detected among these areas; the majority of cases originated from the transfusion centres of Porto Velho, Rondônia State and Macapá, Amapá State. Although it is still unclear whether APC individuals may act as reservoirs of the parasite, efficient screening of APCs and malaria patients in Brazilian blood services from endemic areas needs to be improved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Polymorphism in the IL-1β promoter is associated with IgG antibody response to circumsporozoite protein repeats of Plasmodium vivax

Conselho Nacional para o Desenvolvimento Científico e Tecnológico (CNPq) ; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Brazil (CAPES – DS and PDSE) – Finance Code 001São Paulo State University. Graduate Program in Biosciences. São José do Rio Preto, SP, Brazil.Lisboa University. Tropical Medicine and Hygiene Institut. Global Health and Tropical Medicine. Lisboa, Portugal.Federal University of Sergipe. Department of Biology. Aracajú, SE, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Imunogenética da Malária Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Microscopia Eletrônica. Ananindeua, PA, Brasil / Universidade Federal do Pará. Belém, PA, Brasil.Fluminense Federal University. Center of Microorganisms Investigation. Niterói, RJ, Brazil.Fluminense Federal University. Center of Microorganisms Investigation. Niterói, RJ, Brazil.Fluminense Federal University. Center of Microorganisms Investigation. Niterói, RJ, Brazil.Fundação Oswaldo Cruz. Oswaldo Cruz Institute. Laboratory of Malaria Research. Rio de Janeiro, RJ, Brazil.São Paulo State University. Graduate Program in Biosciences. São José do Rio Preto, SP, Brazil.Fundação Oswaldo Cruz. Oswaldo Cruz Institute. Laboratory of Immunoparasitology. Rio de Janeiro, RJ, Brazil.São Paulo State University. Graduate Program in Biosciences. São José do Rio Preto, SP, Brazil / Fluminense Federal University. Center of Microorganisms Investigation. Niterói, RJ, Brazil.BACKGROUND: It is well established that infection by Plasmodium vivax is a result of host-parasite interactions. In the present study, association with the IL1/IL2 cytokine profiles, anticircumsporozoite protein antibody levels and parasitic loads was evaluated in individuals naturally infected with P. vivax in an endemic area of the Brazilian Amazon. METHODS: Molecular diagnosis of P. vivax and variants was performed using the PCR-RFLP method and IL1B -511C>T, IL2 -330T>G and IL2+114T>G polymorphisms were identified using PCR-RFLP and allele-specific PCR. IL-1β and IL-2 cytokine levels were detected by flow cytometry and circumsporozoite protein (CSP) antibodies were measured by ELISA. RESULTS: Three variants of P. vivax CSP were identified and VK247 was found to be the most frequent. However, the prevalence and magnitude of IgG antibodies were higher for the VK210 variant. Furthermore, the antibody response to the CSP variants was not associated with the presence of the variant in the infection. Significant differences were observed between the single nucleotide polymorphism (SNP) -511T>C in the IL1B gene and levels of antibodies to the VK247 and P. vivax-like variants, but there were no associations between SNPs in IL1 and IL2 genes and their plasma products. CONCLUSIONS: Individuals with the rs16944 CC genotype in the IL1β gene have higher antibody levels to the CSP of P. vivax of VK247 and P. vivax-like variants